2009 Peugeot 308 1.6 VTI

tammy66

For some reason the radiator cooling fan has started to come on virtually when i start up the car and runs for about 5 mins after i switch off can anyone help

angrycrow

The VTI engines have a known issue with the coolant temp sensor. It corrodes internally causing two issues. The first not very obvious issue is that coolant travels up the cable by capillary action until it reaches the ECU where it corrodes the connections to the ECU causing lots of random electric issues. If you are lucky the other issue happens first and the connector plug corrodes off the sensor. On the 207 with this engine this is normally accompanied by a very obvious red coolant too hot warning light on the dash and a message stating stop engine at the same time the cooling fans switches on and runs constantly and continues for around 5 minutes after the engine shuts down.

If this does turn out to be the problem you can replace the coolant sensor which are inexpensive and easy to change but will eventually fail again in the same way. Or you can replace the thermostat with the completely redesigned unit from Peugeot main dealer that changed the sensor wiring, you also need to buy a patch lead to make your existing wiring work with the modified thermostat. All in it comes to around £180 plus fitting. DIY fitting is possible but you need to remove the intake ducting, air filter housing, ecu and battery tray to be able to get to the back of the engine to remove or refit the clip that holds the thermostat into the coolant pipe, and it is a pig to get the clip back on.

mattyprice4004

10/10 for one of the most detailed and informative posts I've ever seen on this forum!